Agent skill · software engineering · jeremylongshore
retellai-hello-world
Retell AI hello world \u2014 AI voice agent and phone call automation.\n\
Why this skill is useful
Provides specific API commands and workflows for creating voice agents and making phone calls with Retell AI that the AI wouldn't reliably generate on its own.
What it needs
Requires retell-sdk installed locally. Requires retellai account access. About 2k tokens when loaded. Last updated 2026-08-07. 2,604 stars on the source repository.
What this skill does
Retell AI Hello World Overview Create your first Retell AI voice agent and make a test phone call. Prerequisites Completed retellai-install-auth A phone number registered in Retell AI Dashboard (or use web call for testing) Instructions Step 1: Create an LLM Configuration Step 2: Create a Voice Agent Step 3: Make a Test Phone Call Step 4: Or Test with Web Call Step 5: Check Call Status Output LLM configuration with custom prompt Voice agent with selected voice Test call initiated (phone or web) Call status and transcript retrieved Error Handling Error Cause Solution ------- ------- ---------- 422 Invalid voiceid Unknown voice List available voices in Dashboard 400 No phone number Number not registered Register number in Dashboard first Call not connecting Destination unreachable Try web call for testing Examples Validate a first agent with a web call before using a phone number Create a development agent with a short greeting and no external tools, then exercise it through the web-call interface using synthetic inputs. Confirm the selected voice, expected greeting, disconnect behavior, and redacted transcript. Only after this evidence is reviewed should a team attach a test phone number; production routing remains separate until the agent has a versioned preview and a documented fallback path. Resources Retell AI Documentation Create Phone Call Next Steps Configure agent behavior: retellai-core-workflow-a
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills jeremylongshore/retellai-hello-world--f165ee